For those with stuttering issues on PC, the note I was given with the review copy was basically to make sure the in game v sync setting was set to On if you were playing in borderless fullscreen.
I ended up just switching to Fullscreen and had no problems after, but theoretically Borderless + Vsync on should work. They said it was going to be addressed in a patch.
A quick and dirty benchmark: I played at max settings 4k on a 2080TI/9900k-at-5Ghz, averaging something like 55 fps. 70 and up in indoor areas, down to high 40s a the most intense outdoor areas. Turning down shadows or sliding the dynamic resolution down a tad were both quick ways to gain some easy frame back.
With a 2080 Ti @ 3440x1440, I'm only getting like 70fps in the first city and not even at ultra. Had to turn down settings to get the stuttering to stop despite the v-sync settings and it being at Fullscreen.